Motor operated can opener

ABSTRACT

A reduction gearing relating an electric motor for driving a feed wheel and a driving shaft carrying the feed wheel includes helical gears at least one of which is adapted to be displaced axially by the thrusting force resulting from the reaction force of the can opening operation. This thrusting helical gear is either mounted tightly on a thrusting shaft for movement of the gear with the shaft or alternatively, the helical gear may be mounted loosely for thrusting movement on a shaft adapted not to thrust. A resilient interconnecting member is actuated by the thrusting movement of the helical gear and makes a latching piece engage a pivoted hand lever carrying a rotary cutter, thereby maintaining the hand lever in the lowered or can severing position. The disappearance of the reaction force results in the disengagement between the hand lever and the latching piece and the displaced helical gear is returned by the restoring force of the resilient interconnecting member.

United States Patent [1 1 Yamamoto 1 Sept. 24, 1974 1 MOTOR OPERATED CANOPENER [75] Inventor: Osamu Yamamoto, Nagoya, Japan [7 3 Assignee:Kabushikikaisha Aichidenkikasakusho, Kasugia-shi,

Aichi-ken, Japan [22] Filed: May 21, 1973 [21] Appl. No.: 362,224

Primary ExaminerAl Lawrence Smith Assistant ExaminerGary L. SmithAttorney, Agent, or FirmWilliam Anthony Drucker [57] ABSTRACT Areduction gearing relating an electric motor for driving a feed wheeland a driving shaft carrying the feed wheel includes helical gears atleast one of which is adapted to be displaced axially by the thrustingforce resulting from the reaction force of the can opening operation.This thrusting helical gear is either mounted tightly on a thrustingshaft for movement of the gear with the shaft or alternatively, thehelical gear may be mounted loosely for thrusting movement on a shaftadapted not to thrust. A resilient interconnecting member is actuated bythe thrusting movement of the helical gear and makes a latching pieceengage a pivoted hand lever carrying a rotary. cutter, therebymaintaining the hand lever in the lowered or can severing position. Thedisappearance of the reaction force results in the disengagement betweenthe hand lever and the latching piece and the displaced helical gear isreturned by the restoring force of the resilient interconnecting member.

6 Claims, 4 Drawing Figures PATENIED $EP24I974 SHEEI 2 BF 2 FIG.3

MOTOR OPERATED CAN OPENER BACKGROUND OF THE INVENTION In a conventionalmotor operated can opener, a can is opened in such a manner that arotary cutter penetrates the outer edge of a can lid with the end seamof the can disposed on a feed wheel and the can is rotated by the feedwheel. For the purpose of maintaining the rotary cutter in its cansevering position during a can opening process, either the rotary cutteror the feed wheel is adapted to be movable against a housing and isdisplaced in accordance with the variation of the reaction forceexerting on the feed wheel during can opening process, thereby making acomplicated and delicate holding mechanism for a rotary cutter carryinghand lever or handle to work. Because either the rotary cutter or thefeed wheel is displaced just when the rotary cutter is penetrating thecan lid, utilization of such a complicated holding mechanism requiresskillful operations of the handle to make the rotary cutter penetratethe can. Further, such a conventional can opener is expensive in itsmanufacturing cost because of the complicated structure for makingmovable either the rotary cutter or the feed wheel and has thedisadvantage of possible troubles.

SUMMARY OF THE INVENTION The present invention improves the inotoroperated can opener in construction and operation in order to eliminatethe disadvantages mentioned above and its object is to provide a motoroperated can opener simple in construction with which any one withoutmechanical skill can open cans easily. The feature of the presentinvention lies in the introduction of helical gears in the gearing fortransmitting torque from the electric motor to the feed wheel. At leastone of the helical gears is mounted for thrusting motion. The hand levercarrying the rotary cutter is pivoted adjacent the outer end of thefront vertical wall of a housing for vertical swinging motion and isadapted to be latched in its can severing position by the cooperation ofa latching piece and a resilient interconnecting member actuated by thehelical gear for thrusting. When the reaction force appears and theelectric motor is loaded as the result of the can opening operation, thehelical gear is not only rotated by the increased driving force but alsois pushed forwardly, thereby actuating the resilient interconnectingmember to make the latching piece maintaining the hand lever in the cansevering position. When the electric motor is unloaded, the thrustedhelical gear is returned by the resilient interconnecting member and thehand lever becomes free.

It will be understood from the salient relationships just described andfollowing descriptions that the present can opener is simplified instructure and operation by the elimination of the conventionalcomplicated mechanism prepared specially for latching the hand lever.Thus, the can opener is inexpensive and can be operated satisfactorilyby users mechanically unskilled.

In the drawings FIG. 1 is a front elevational view ofa motor operatedcan opener;

FIG. 2 is a rear elevational view of the can opener with a rear coverbeing taken away;

FIG. 3 is a fragmentary view partly in vertical section of the canopener showing the unloaded situation;

FIG. 4 is a view similar to that of FIG. 3 but showing the can severingsituation.

Referring to the figures, a motor operated can opener according to thepresent invention comprises a housing A, can feeding mechanism B, alever latching means C, a cutter assembly D and a switching structure E.The housing A comprises a base plate 10, side walls 11, a front wall 12,a top plate 13, and a rear cover (not shown). On the inner surface ofthe front wall 12, a frame 14 is secured on which the can feeding mechanism B and the latching means C are mounted. A can supporting lug 15 tohold a can on its side wall is attached by means of screws adjacent thecenter of the outer surface of the front wall 12. In the can feedingmechanism B, a peripherally toothed feed wheel 16 is mounted on theouter extreme of a driving shaft 17 which projects through the frontwall 12 and the frame 14 and is journaled rotatably in a bearing boss 18extending inwardly from the fram 14. In order to drivingly relate anelectric motor 19 mounted in the housing A and the driving shaft 17,there is provided a reduction gearing 20. The reduction gearing includesa large helical gear 21 mounted on the inner extreme of the drivingshaft 17. A helical gear 22 of small diameter being in mesh with thelarge helical gear 21 and a thrusting large helical gear 23 are mountedtightly on a thrusting shaft 24 one end of which is received rotatablyand reciprocatingly in a bearing support 25 formed on the frame 14. Thethrusting helical gear 26 formed on the shaft of the electric motor 19.Instead of using the thrusting shaft 24, the thrusting helical gear 23may be mounted loosely for thrusting movement on a shaft adapted not tothrust. The helical threads of the gearing 20 are so oriented that theaxial component resulting from the reaction force-of the canopeningoperation can displace the thrusting gear 23 from the positionshown in FIG. 3 to that shown in FIG. 4. Now in the latching means C, aninverted Y-shaped resilient interconnecting member 27 is secured on theframe 14 at its both extreme ends of the limbs 27' by means of screws28. The forked portion of the resilient interconnecting member 27 isintersected by the thrusting shaft 24 to be bent by the thrustinghelical gear 23 and the upper end of the resilient interconnectingmember 27 is secured on the inner end of a latching piece 29 which iscontained reciprocatingly in a cylindrical holder 30 formed integrallywith the upper end of the frame 14. The resilient interconnecting member27 not only relates the thrusting helical gear 23 and the latching piece29 but also serves as a means for biasing the gear 23 to return it tothe position of H6. 3. The elastic biasing force exerted by theresilient member 27 is adjusted to be weaker than the axial thrustingforce resulting from the reaction force of the can opening operationthereby allowing the thrusting shaft 24 to displace in the directionindicated by an arrow 31 but to be enough to return the thrustinghelical gear 23 when the feed wheel 16 is unloaded or undriven. Next inthe cutter assembly D, a hand lever 32 is positioned against the frontwall 12 and is pivoted by means of a pivot 33 and a nut 34 for verticalswinging movement. The hand lever 32 has an upper face 35 and a verticalfront face 36 on the.

lower edge of which a'hook 37 is provided as a member to engage thelatching piece 29 when the hand lever 32 is lowered to move theswitching structure E to its circuit closing position. The hand lever 32carries a planar spring 38 which is disposed on the upper edge of thecan to be opened in order to prevent vibrations involved in the cansevering operation and to raise the hand lever 32 after the completionof the can opening operation. A circular rotary cutter 39 is mountedrotatably on a stud 40 extending from the hand lever 32 in a inclineddownward direction. Adjacent and over the mount of the rotary cutter 39is projecting an arm 41 from the hand lever 32. A headed hanger 42 isprovided in an aperture of the arm 41 and a permanent magnet 43 issecured on the lower end of the hanger 42. The switching structure E iscontained within a switch box 44 and includes a push button 45projecting through the top plate 13. The push button 45 engages aresilient movable contact 46 at its lower end and the movable contact 46cooperates a fixed contact 47. The contacts 46 and 47 are adapted tocontact each other by the downward movement of the push button 45depressed by the hand lever 32 and to close the motor energizingcircuit.

In the operation of the device, the hand lever 32 is raised from theposition of FIG. 1 and then the end seam 48 of a can is placed on thefeed wheel 16. Then, lowering the hand lever 32 makes the rotary cutter39 penetrate into a can lid 49 near its outer edge and moves theswitching structure E into its circuit closing position. The electricmotor 19 thus energized rotates the feed wheel 16 through the gearing20, thus feeding the can and the rotary cutter 39 severs the can lid 49.At the same time, the helical gear 22 and the helical gear 23 aredisplaced forwardly of the housing A from the position of FIG. 3 to thatof FIG. 4 keeping meshing engagement with gears 26 and 21 on account ofthe axial force resulting from the reaction force of the can openingoperation and exerting on the thrusting shaft 24. The resilientinterconnecting member 27 is bent to establish the engagement betweenthe latching piece 29 and the hook 37, thereby latching the hand lever32 in its can severing position. When the reaction force disappears asthe completion of the can opening operation, the gears 22 and 23 arereturned from the position of FIG. 4 to that of FIG. 3 by the biasingforce of the resilient member 27 which also makes the latching piece 29disengage the hook 37. The hand lever 32 which has been made free, israised slightly by the restoring force of the planar spring 38 or themovable contact 46 to open the motor energizing circuit. After raisingthe hand lever further, the can be removed from the can opener. The canlid 49 cut off is attracted and held by the magnet 43, being preventedfrom dropping in the can.

What we claim is:

1. A motor operated can opener comprising a housing, an electric motormounted in said housing, a driving shaft extending rotatably through thefront wall of said housing, a peripherally toothed feed wheel mounted onthe extending end of said driving shaft, and

being adapted to engage the lower end of the end seam of a can, areduction gearing for relating said feed wheel and said electric motor,said gearing comprising a train of helical gears and one of said helicalgears being adapted to be displaced axially under the thrust resultingfrom the working gearing, a hand lever positioned against and pivoted tosaid front wall for vertical swinging motion between positions adjacentand away from the feed wheel, a rotary cutter for cutting the lid of thecan and carried by said hand lever, a switching structure contained insaid housing, said switching structure including a push buttonprojecting through the top plate of said housing and adapted to bedepressed to move said switching structure into the motor energizingposition, a latching piece extending reciprocatingly through said frontwall, said latching member being adapted to engage the hand leverthereby latch said hand lever in its lowered or can severing positionand a resilient interconnecting member relating said thrusting helicalgear of the reduction gearing and said latching piece, the elastic forceof said resilient interconnecting member being weaker than theaxialthrusting force resulting from the reaction force of can openingoperation and exerting on the thrusting helical gear to establish theengagement between said latching piece and said hand lever ondissapearance of said reaction force.

2. A motor operated can opener described in claim I in which saidthrusting helical gear is mounted tightly on a thrusting shaft supportedreciprocatingly against said housing.

3. A motor operatedcan opener described in claim 1 in which saidthrusting helical gear is mounted loosely on a shaft for reciprocatingmovement.

4. A motor operated can opener described in claim I in which saidresilient interconnecting member is an inverted Y-shaped member securedagainst said housing at two limb'portions, engaging the latching pieceat the other end and being actuated by the thrusting helical gear at itsintermediate forked portion.

5. A motor operated can opener described in claim I in which saidresilient interconnecting member is an inverted Y-shaped member securedagainst said housing at two limb portions, engaging the latching pieceat the other end and having its forked intermediate portion engaged bysaid thrusting helical gear and is adapted to bend resiliently whenactuated by the thrusting helical gear and to function to return saidthrusting helical gear on the disappearance of the can opening reactionforce exerting on said feed wheel.

6. A motor operated can opener described in claim 1 in which said handlever carrying said rotary cutter comprises a top face and a verticalface with its lower portion bent towards said front wall of the housingto form a latched member and this latched member is engaged by saidlatching piece extending through said front wall thereby maintainingsaid hand lever in the can opening position during the can openingoperation.

1. A motor operated can opener comprising a housing, an electric motormounted in said housing, a driving shaft extending rotatably through thefront wall of said housing, a peripherally toothed feed wheel mounted onthe extending end of said driving shaft, and being adapted to engage thelower end of the end seam of a can, a reduction gearing for relatingsaid feed wheel and said electric motor, said gearing comprising a trainof helical gears and one of said helical gears being adapted to bedisplaced axially under the thrust resulting from the working gearing, ahand lever positioned against and pivoted to said front wall forvertical swinging motion between positions adjacent and away from thefeed wheel, a rotary cutter for cutting the lid of the can and carriedby said hand lever, a switching structure contained in said housing,said switching structure including a push button projecting through thetop plate of said housing and adapted to be depressed to move saidswitching structure into the motor eneRgizing position, a latching pieceextending reciprocatingly through said front wall, said latching memberbeing adapted to engage the hand lever thereby latch said hand lever inits lowered or can severing position and a resilient interconnectingmember relating said thrusting helical gear of the reduction gearing andsaid latching piece, the elastic force of said resilient interconnectingmember being weaker than the axial thrusting force resulting from thereaction force of can opening operation and exerting on the thrustinghelical gear to establish the engagement between said latching piece andsaid hand lever on dissapearance of said reaction force.
 2. A motoroperated can opener described in claim 1 in which said thrusting helicalgear is mounted tightly on a thrusting shaft supported reciprocatinglyagainst said housing.
 3. A motor operated can opener described in claim1 in which said thrusting helical gear is mounted loosely on a shaft forreciprocating movement.
 4. A motor operated can opener described inclaim 1 in which said resilient interconnecting member is an invertedY-shaped member secured against said housing at two limb portions,engaging the latching piece at the other end and being actuated by thethrusting helical gear at its intermediate forked portion.
 5. A motoroperated can opener described in claim 1 in which said resilientinterconnecting member is an inverted Y-shaped member secured againstsaid housing at two limb portions, engaging the latching piece at theother end and having its forked intermediate portion engaged by saidthrusting helical gear and is adapted to bend resiliently when actuatedby the thrusting helical gear and to function to return said thrustinghelical gear on the disappearance of the can opening reaction forceexerting on said feed wheel.
 6. A motor operated can opener described inclaim 1 in which said hand lever carrying said rotary cutter comprises atop face and a vertical face with its lower portion bent towards saidfront wall of the housing to form a latched member and this latchedmember is engaged by said latching piece extending through said frontwall thereby maintaining said hand lever in the can opening positionduring the can opening operation.